Power Packs keep going bad

[Eric45653]

Hi all! I read the posts all the time. But this time I had to register. <br /><br />Its a 1976 Johnson 135hp Powershift II. I am about to install my 2nd power pack this season. First time it went out, I was cruising at almost full throttle for about an hour. Then just yesterday, I pulled into the dock at my marina to have the "poop pumped" out of the black tank. It wouldnt fire and had to get pushed back.<br /><br />Is this just dumb luck...or is there something else going on? Thx Eric

 

[R.Johnson]

Re: Power Packs keep going bad

This time before you replace the pack, check out, or have checked out the intire system. Be sure and check out all grounds, and find out what the charge coil, and sensor output is.

 

[Tom Scully]

Re: Power Packs keep going bad

Any voltage applied to the engine kill wire, (Black/yellow on the ignition switch), will damage a power pack.

 

[mikeyzx2]

Re: Power Packs keep going bad

Hey Eric, I was told recently by my local wrench that faulty stator will cause packs to fail. Check into rectifier also, and let us know what ya find out.

 

[Eric45653]

Re: Power Packs keep going bad

Tom and Mikey, <br /><br />Speaking of rectifier.....Yesterday, I hooked up a tachometer to the motor. I hooked it up to the #7 terminal on the terminal block (which also goes to the rectifier). The engine did quit once, but started right back up. Do you think this might have had someting to do with it all????

 

[MCM]

Re: Power Packs keep going bad

Eric,<br /><br />I think you may need to investigate the wiring on the terminal block. to my knowledge you should have a 3 wire rectifier and the red wire should connect to terminal #3, the y/gray wire to term. #2 which would also have the gray tach lead, and the yellow wire to #1. If the wires at the terminal block have been attatched incorrectly this could be leading to some of your problems. If you have an OEM service manual it will have the proper wiring diagram.<br /><br />Ironically the BRP site doesn't even list a 1976 135hp motor. Nor does Ishopmarine

 

[Eric45653]

Re: Power Packs keep going bad

Hi MCM, It is a 3 wire rectifire. I checked my manual and the wiring as you described is correct (if you go right to left-instead of left to right). I have a 8 terminal block with the #1 position empty (far left side). Also....im sorry, its a 1974 johnny 135.<br /><br />Im going to go ahead and replace the PP again (thinking that i may have done something when i hooked up the tach). I would like to know exactly what the rectifire does, and is it worth replacing with the PP????

 

[Trent]

Re: Power Packs keep going bad

When an engine starts blowing power packs repeatedly, especially on the same cylinders, replace the ignition coils on those cylinders. The inductive kickback from a bad coil can destroy the packs, even if the coils check good with all known tests. A stator that test good can also be sending spike voltages to the packs causing them to fail repeatedly.

 

[MCM]

Re: Power Packs keep going bad

Eric, I think you should do as R.Johnson suggested and troubleshoot the ign. system before replacing any parts. Your manual will describe the process, if you have a DVM (digital volt/ohm meter) you should be able to locate the source of the problem fairly quickly.<br /><br />Joe Reeves has some excelent posts and instructions on testing. Here's one for testing the rectifier.<br /><br />(Small Rectifier Test)<br />(J. Reeves)<br /><br />Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.<br /><br />Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.<br /><br />Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.<br /><br />Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.<br /><br />Hope you don't mind Joe!<br /><br />Also visually inspect the stator for any cracks or any kind of sticky residue dripping off. Also inspect ign. coils for cracks. Check all wires for any chafing, corrosion or loose connections.<br /><br />To check for a bad start switch disconnect the large red plug and check for spark by jumping it at the sarter solenoid, you should do this with plugs removed (if the motor starts you wouldn't be able to shut it off without pulling plug wires or disconnecting the fuel line and letting it run out of gas.<br /><br />This link also has some good info on t/shooting.<br /><br /> web page

 

[Joe Reeves]

Re: Power Packs keep going bad

The usual cause of having those type powerpacks fail repeatedly is having a very small of voltage applied to the Black/Yellow wire at the pack. Test as follows.<br /><br />Disconnect the Black/Yellow wire at the powerpack.<br /><br />Insert either a ampere meter or a volt meter set to its lowest DC voltage reading between that Black Yellow wire and ground.<br /><br />With the ignition key in the OFF position, observe the meter reading. Now turn the ignition key to the ON position and again observe the meter reading.<br /><br />Any reading, movement of the meter needle, would indicate that battery voltage is being applied to that Black/Yellow wire. If a reading is present, remove the other end of that Black/Yellow from the raised terminal of the ignition switch.<br /><br />If the reading ceases to exist when the Black/Yellow wire is removed from the ignition switch, replace the switch. If the reading continues to exist, there would be a short of some kind in either the engine or instrument wiring harness.... to determine which, simply unplug the large RED electrical plug at the engine which would eliminate the instrument cable.

 

[kci5477]

Re: Power Packs keep going bad

I am not sure I agree with MCM on the wiring diagram for the terminal block.<br /><br />Terminal 8 is closest to the carbs and Terminal 1 is closets to the spark plugs.<br /><br />If you want a copy of diagram let me know and I can email it to you.<br /><br />My manual shows.<br />1 is vacant<br />2 is Purple/White<br />3 is Purple<br />4 is Purple/Yellow<br />5 is Yellow<br />6 is Yellow/Gray<br />6 and 7 are jumpered together<br />7 is gray to tach and Yellow/Gray from rect.<br />8 is red from solenoid and red from rect.<br /><br />The 1974 model does not have the safety switch.<br /><br />Hope this helps.

 

[MCM]

Re: Power Packs keep going bad

Yea he has the manual and already checked, My mistake, I wasn't aware they got dislexic on that motor

 

[Eric45653]

Re: Power Packs keep going bad

Kemper, MCM, Joe, and Trent,<br /><br />This Thursday, I am going to do all the checks you recommend. I have a PP and coils coming from "boatbuddy.com". I will test the rectifire as described. I will let you know what i find out. Im sure it will run....but for how long, is the question.